When Sylvain Tesson left the colourful yellow houses of the French Riveria for a ski trek across the Alps with his friend Daniel du Lac, a high-altitude mountain guide, he didn't know what exactly would await him. Over the course of four years, from 2018 to 2021, they ascended high into the Alps in winter, following the curve of the mountains from the Mediterranean to the Adriatic, entering into a white world entirely of snow, bitterly cold and overlooked...